Ceiling-block



(No Model.)

D. A. TOMPKINS.

CEILING BLOCK. No. 440,934. PatentedNov. 18, 1890.

UNITE STATES PATENT EEICE.

DANIEL A. TOM-PKINS, OF CHARLOTTE, NORTH CAROLINA.

CEILING-BLOCK.

SPECIFICATION forming part of Letters Patent N 0. 440,934, dated November 18, 1890.

I Application filed December 31, 1889. Renewed October 20, 18 90. Serial No. 368,713. (No model.) I

To all whom it may concern.-

Be 1t known that I, DANIEL A. ToMPKINs,

. a citizen of the United States, residing at declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to that class of electrical devices known as electrical cut-outs, whose functions are to attach or remove shunting-circuits, especially for incandescent lamps, to and from the main circuit.

The objects of my invention are to so construct these cut-outs that the operation of wiring and unwiring the same may be facilitated and the cost of the plant reduced.

To this end my invention consists in arranging the screws whose heads hold the maincircuit wires against the contact-strips at an angle to the confining sides of said cont-actstrips, instead of parallel thereto, as in constructions heretofore used, whereby a slight turn of the screw may enable the wires to be withdrawn from the cutout. I preferably produce this angle by making the confining sides of the contact-strips sloping.

To more fully explain the nature of my invention and the manner of carrying the same into effect, I will now proceed to describe the same in detail, reference being had to the accompanying drawings, in which- Figure I represents an inverted plan of the upper portion of a cut-out embodying my invention, showing the interior construction; Fig. 11, a plan of the lower half; Fig. III, a vertical central section of the entire cut-out, the line of section being indicated at 0000, Fig. I; Fig. IV, a detail view of a contact-strip, showing a modified form; Fig. V, a similar View of the old form of contact-strip.

The same letters designate the same parts in all the views.

In the drawings, a represents the base or upper section of my cut-out. This section is secured in position to the wall or other fixtures by screws or otherwise and is made of insulating material, such as wood. It is provided with the two parallel channels 9 g to receive the large wires of the main circuit,

the insulation of which is removed sufficiently to bring the naked wires in contact with the metal contact-strips b I), attached to the base a. These contactstrips are in the form shown in Fig. I-that is to say, they are attached to the base so that their outer orcontactends I) are flush, or approximately so, with the bottom of the base and their inner ends. Those against which the main wire impinges are provided with two bends 19 b adjoining each other, the latter resting on the bottom of the cupped interior of the base and being secured thereto. The wires g, resting in the channel 9, are held against the contact-strips b by the heads of the headed binding-screws e, threaded into the outer bend 5 It is in the relation that these screws occupy with respect to the side or bend b that my invention resides. This consists, essentially, in arranging the axis of the screw 6 at an angle to the said side 19 instead of parallel therewith, as heretofore. I may produce this angle either by having the screw vertical and the side Z2 sloping, as shown in Fig. III, or I may make side 19 vertical and the screw inclined, or I may have both the side 13 sloping and the screw inclined, as in Fig. IV. The advantage of this arrangement is that a large wire g may be removed by a slight slacking of the screw and without removing the same, as will be seen by referring to Figs. III and IV, where the dotted lines indicate the position of the screw when slacked, and also show that in that position the opening within the head of the screw is large enough to allow the wire g to pass. This effect could not be obtained in the old construction, which is indicated in Fig. V. There it is necessary to entirely remove the screw to wire or unwire.

c designates the lower half or rosette of the cut-out. It is also made of insulating material and with the central passage h for the passage of the shunting-strand leading to the lamp. It is also provided with the two contact-strips (Z, of cond ucting material, bent similarly to the steps b and so attached to the rosette at its inner cupped face that when the base and rosette are brought together, as in Fig. III, the strips will contact. It will be noted that these strips are provided with the binding-screws t t, and that the interior cupped face of the rosette is provided with two clamping-contacts m m, of conducting material, each having binding-screws u t. The two Wires of the shunting-strand w are attached to these clamping-contacts by the binding-screws 15, and thence pass through the passage h to the lamp. Fusible wires f8 fs are secured between the binding-screws n and t to break the current in the shunting-strand when the main current becomes abnormal. One of the contact-strips d is provided with a recess d and the other with a tongue 01 for the purpose of connecting the rosette with the base, which is provided at its contactstrips with the two screws .9 3.

When it is desired to unite the rosette to the base, the recess (1 is slipped under the head of the screw .9, and the rosette is swung around until the tongue 61 strikes the other screw and lies under its head. The two screws are then tightened and the circuit is complete.

The circuit takes this course: from the main wire g through the one set of contact-strips b and d, through one fusible Wire fs, through one clamping-contact m, through the Wire w and the lamp, thence back through the other wire w, clamping-contact m, fusible Wire fs, strips d b, and main wire g in the order stated.

The advantage of having the contact ends of the strips 12 01 extending outwardly toward the periphery of the cut-out is that this arrangement obviates the danger of having one of the contact ends of the strips d accidentally crossing the two contact ends b b, and thus establishing a short circuit.

Having now described the best means for carrying my invention into effect, What I claim, and desire to secure by Letters Patent, 1s

1. In a cut-out for shunting circuits, a contact-strip having two bends adjoining each other, in combination with a headed bindingscrew threaded into one bend and arranged at an angle to the other bend, substantially as and for the purpose described.

2. In a cut-out for shunting circuits, a contactstrip having a sloping side or bend and an outwardly-extending bend adjoining the said sloping bend, in combination with a headed bindingscrew threaded into the outwardly-extending bend, substantially as and for the purposes set forth.

3. In a cut-out for shunting circuits, a contact-strip I), provided with a sloping side or bend b and the downwardly-extendinghorizontal bend b adjoining the bend 19 in combination with a vertical headed binding-screw e, threaded into a downwardly-extending bend b substantially as and for the purpose described.

In testimony whereof I affix my signature in presence of two Witnesses.

DANIEL A. TOMPKINS.

Witnesses:

PAUL BIGELOW, J O. WATsoN. 

